Method of making porous cement



LAijibiH Paten ed Oct. 27, 1931 I I UNITED STATES PATENT OFFICE ERNESTWALTER, OF NEWARK, NEW JERSEY METHOD OF MAKING POROUS CEMENT No Drawing.Application filed July 31, 1926. Serial No. 126,339.

This invention relatestoaprocess for makpoint before it will actuallyevaporate and ing porous cement and similar material by produce vaporswhich in turn expand the adding to any ordinary cement mix volatilecementitious mass. material and a very small amount of metallic Ibelieve this sluggishness is due to the powder. absorption of the finedrops of volatile liquid 55 This application is an improvement over bythe solid ingredients which absorption the process set forth in myapplication filed prevents the volatile agent from evaporating April 5,1924, N 0. 704,492. 11 my previous at its boiling point.

application I describe a process which pro- The addition of the metallicowder gives duces stones, blocks, slabs, and other forms of a muchquicker and Better actlon as combuilding elements which are waterproof,firebines with the alkali in thg h%draulic cm, proof and are light inweight compared with era m 1 r0 en as w 1c 1n expan the ordinarynon-porous cement. mmfiismall degree. This In my previous applidafic irl r' describe the partial opening of the mix accelerates the 15 use ofa volatile material whether solid or evaporation of the volatile liquidand the ex-- liquid, WhlC 1s mlxe m the cement and panding of the massoccurs at a temperature other ingredientfilmmc cevery near the boilinpoint of the volatile ment, and the necessary amount of water. agent. Inthis way, provide an initial ex- The material that is placed in this mixand pandin and openm up and the establishthoroughly distributed throughit, is insolument oi? fine bubbles y the metallic powder ble in waterand has a boiling temperature and an increased and subse uent ex andinunder the boiling point of water at the atmosb the eva oration of e voa. 1 e 1 n1 heric pressure. l am aware that metalllc powders have Thematerials which can be used for this been added to cement mixtures forthe pur- 5 purpose are, for instance, carbon Etrachlopose of making themass porous by the genride carbon disulphjdg aso 1ne nzo eration ofhydrogen gas. But they have E5351... an s1m1 ar materials. This matebeenused alone and thus used it requires a 113. 15 eated thoroughly in thecement mix quantlty of metallic powder as from oneuntil it is emulsifiedand is in finely divided tenth to one-half percent of the weight of the30 state throghout the whole body. This mass cement. so is exposed to atemperature below the boil- In this invention where I use the vapor ingpoint of water but above the boiling temproduced by a volatile liquid asthe fundaerature of the volatile material. This heatmental agent for theincrease in volume, I mg is usually done by live steam and the finefindthat I require only one-tenth to one- 35 ly divided volatile materialbecomes gaseous twentieth of the amount of metallic powder and fillsthewhole mix with a large number which would be required if the powderis of gas bubbles which make the body porous used alone. In other words,I need only oneand eatly increases its volume. This is hundredth to onetwo-hundredths part of medone' efore the cement sets and the result istallic powder to the weight of cement. In 40 a hard porous body with aspongy appearthis way, I save a considerable amount of meance. tallicpowder.

The improvement consists in adding to the The volatile material which Iuse is very cement mix while it is still plastic and usualcheap as onlya very small quantity of it is 1y at the same time that the volatilematerial required. Due to the heating of the mass is added a smallquantity of metallic powder after it is mixed, I obtain a very quick andpositive set of the cement.

such as zinc iron. or aluminum.

In tm the volatile Instead of hydraulic cement, other cements materialwill be evaporated. It evaporates or materials like sum can be used, butin rather sluggishly and the liquid has to be suthis case it isnecessary to add a small amount perheated considerably above the boilingof alkali in the form of lime soda etc. to

combine with the metallic powder and form the necessary amount ofhydrogen gas for the initial expanding of the mass.

I claim:

1. The process of making artificial stone which comprises mixing aplastic mass of cementitious material containing a small amount of freealkali with water and a small amount of liquid not soluble in water andwhich is more highly volatile than water, adding a small quantit ofabout one onehundredths of the weig t of cement, of metallic powder thatwill produce hydrogen when mixed with water and the alkali in the cementat a temperature of less than 0., heating the mass whereby the powderinitiates a large number of as bubbles and continued heating causes arther expansion by the volatile material.

2. The process of making artificial stone which comprises mixinghydraulic cement containing a small. amount of free alkali andaggregates with water and with a small amount of liquid insoluble inwater and which vaporizes below the boiling point of water and with asmall quantity of about one one-hundredths of the weight of cement mixof metallic powder that will produce hydrogen when mixed with water andthe alkali in the cement at a temperature of less than 100 0., heatingthe mixture so formed whereby the metallic powder causes the initialexpansion of the mass and the volatile material causes a continued andmajor expansion thereof.

In testimony whereof I afiix my signature.

E. WALTER.

